The Crab Nebula, as it’s commonly known, is connected to one of the earliest recorded supernova explosions. In 1054 AD, Chinese Astronomers saw the explosion of this supernova as an incredibly bright star in the sky lasting about two weeks, before fading. Now, nearly 1000 years later, the explosion is still happening as an expanding shock front rich in heavy elements moves through the interstellar medium. When the shock front hits dust or gas it is slowed down, giving the resulting nebula a unique shape. In this case, it looks like a crab. The supernova wasn’t exactly the death of the original...
Predicting the death of a star is easy. If we know how massive it is, and what stage of life it’s in, we know that it should explode eventually, within a set timeframe of many hundreds of thousands, or even millions of years. But on human timescales, that is just not good enough. What if we could predict a supernova explosion within a few months? For something that lives for so long, this would be a triumph in our understanding of the universe. Over the past couple of years, this is exactly what happened. Here’s how. A supernova is one of the most...
How do stars lose mass? For a star like the Sun, it shoots out a swath of charged particles into space and sheds mass at a rate of 4 million tons per second! Though even at this rate, the Sun only loses 1% of its total mass every 160 Billion years, so it’s not disappearing anytime soon. For more massive stars, the process can become complex and strange. The red hypergiant VY Canis Majoris, one of the largest known stars, is about 40 times as massive as the Sun, but humungous in scale. If this star were to replace the...
One of the greatest scientific discoveries of all time came with the invention of the spectroscope by Joseph Von Fraunhofer in 1814. It enabled us to look out at the universe and realize that the same basic building blocks that made you and I and all other life, were the same things that make up everything else in the cosmos. The tiny atoms in our bodies all started out at the center of a massive star billions of years ago. So naturally, when we talk about the odds of life forming elsewhere, we have to include a study of where...
News always reports the records. The biggest, the loudest, the fastest, the first. When it comes to Astronomy, there are so many new worlds to explore and so much new science to learn, we end up breaking records often. Even with Astronomy being the oldest science, the sheer amount of stuff in the universe means there is always something new and surprising to discover. Today’s episode of ‘Biggest, brightest, hottest’ brings us the move massive binary star system ever found, with two huge, hot stars so close together that they are actually touching, merging their atmospheres together. In the Large...
Remember that amazing high-def photo of M31, the Andromeda Galaxy, from Hubble a few months back? It was able to separate the light from the galaxy into the millions of visible stars that populate its spiral arms. This image is used for far more than the wow factor of seeing another galaxy up close. It allows us to study the entire galaxy and gain insights into the lives of spiral galaxies beyond our own, how they formed, how they evolve, and maybe even how they will eventually die. By looking at the spiral arms of M31, where the youngest and...
How often does a star explode as a supernova in the Milky Way? With as many as 400 Billion stars, you would expect it to happen often But stars live a very long time, and most massive stars take anywhere from a few hundred million to a few billion years to reach maturity and explode. Putting all this together gives us a surprisingly human estimate. A supernova explodes in the Milky Way, on average, once every 50 years, or about once per human lifetime. We can still see remnants of great explosions that happened long ago, still expanding into the...
I am always fascinated by the diversity of colours, shapes, and scenarios that pop up throughout our universe. Even though we can classify things into categories like ‘planetary nebula,’ ‘galaxy,’ ‘dwarf star,’ and such, there is still a huge amount of variability among these categories. The most diverse group may be nebulae, since their shape relies on what elements are present, the environment in which they formed, and how far along they are in their evolution. A great example of a strange and interesting nebula is the PN M2-9, the Twin Jet Nebula. Lying 5,560 light years away, in the...
Type 1a supernova explosions are used by Astronomers as a standard candle for measuring distances in Astronomy. They all explode with the same intrinsic brightness, and so depending on their apparent magnitude, ie how bright they look, we can determine the distance to them. It’s like a 40 watt light bulb. No matter how far away I move it, it’s still 40 watts, even though it looks dimmer if it’s further away. However, a few months ago some research came forward about type 1a supernova explosions, hinting that there may actually be two or more distinct types with slightly different...
I was with my friend and fellow astronomer Jesse Rogerson discussing the fantastic book from xkcd author Randall Munroe, called What if? We were talking about the brilliant analogy used by Munroe when talking about how big a supernova is. The questions asked was “Which of the following is brighter, in terms of the amount of energy delivered to your retina?” 1. A supernova, seen from 150 Million Kilometers, about as far as the Sun is from Earth. 2. The detonation of a Hydrogen Bomb, pressed against your eyeball. What a great question. The answer, surprisingly, is the Supernova, which is...
